Refrigeration apparatus



p i 19441 J. H. ASHBAUGH 2,346,641

. REFRIGERATION APPARATUS Filed June 4, 19 41 WITN SSES: INVENTOR W M,dsHsAuaH F/G- a- WW ATTOR EY REFREGERATKQN APPARATUS of PennsylvaniaApplication June 4, 19411, Serial No. 396,515

Claims.

This invention relates to refrigerator cabinet construction, and moreespecially to a construction which overcomes the warping of panels ofheat-insulating material in a refrigerator cabinet.

In the construction of refrigerator cabinets, fiat, thin panels of rigidheat-insulating material are frequently used as the inner panels ofdoors and other parts of the cabinet. Such panels are not. completelyimpervious to moisture. When a refrigeratordoor embodying such a panelis opened while the refrigerator is in operation and the ambient air ishumid-moisture from the atmosphere condenses on the exposed outersurface of the panel, penetrates the surface thereof and causes thesurface layers of the panel to expand. If the panel is fiatandunsupported, the expansion of the surface layers causes the panel tobulge and it may strike the shelving in the refrigerator cabinet whenthe door is closed. If the rigid panel of heat-insulating material alsoforms a vertical retaining wall for loose heatinsulating material, theoutward bulging of the panel permits the heat-insulating material tosettle so that the upper portions of the door are not properlyinsulated.

It is accordingly an object of the invention to provide a refrigeratorconstruction which prevents the bulging of fiat rigid panels ofheatinsulating material used in the refrigerator cabinet walls. I

A further object of the invention is to forcibly retain a rigid andnormally flat panel of a refrigerator cabinet in a dished or pre-setposition in which expansion of the layers on the concave side of thepanel prevents, bulging of the panel in a direction whieh may interferewith the contents of the interior of the refrigerator.

A further object of the invention is to provide a refrigerator cabinetcomprising rigid low-cost sheets of substantially fiat heat-insulatingmaterial.

These and other objects are effected by my invention as will be apparentfrom the following description and claims taken in acordance with theaccompanying drawing, forming a part of this application, in which:

Fig. 1 is a view in perspective of a refrigerator cabinet embodying adoor constructed in accordance with the invention;

Fig. 2 is a section of the door on the line II-II of Fig. 1; and

Fig. 3 is a section on the line III-III of Fig. 2.

Referring to the drawing for a detailed description of the invention,the reference numeral it represents a refrigerator cabinet embodying afood-storage chamber M and a door l2 for the food-storage chamber. Anevaporator It is located in the upper portion of the food-storagechamber M and several shelves it for supporting the articles to berefrigerated are located beneath the evaporator 53.

The door l2 comprises a dished or curvilinear outer panel it of sheetmetal, the edges ll of 10 which are turned inwardly. A continuous framei8 is secured to the inwardly-turned edges to provide a fiat seatingsurface for the sealing gaskets 89. A brace 2! extends horizontallyacross the opening in the frame it and is spot-welded 15 to the frame itat points 22 at both ends of the brace 2!. The brace 2! is of anL-section, comprising a long leg 23 and a short leg 2t and is bentslightly at its center towards the interior of the door I 2.

The sealing gasket it] comprises an attachment flange 26 and a tubularportion H. An inner panel 28 of thin, rigid heat-insulating materiallies with its edges adjacent to the frame l8 and is secured thereto byscrews 29. The panel may 25 be formed, for example, of a materialpregnated with a'resinous condensate product or may be a paintedcellulose panel. The attachment flange 26 of the gasket l9 lies betweenthe frame l8 and the edges of the inner panel 28, and

'30 is clamped therebetween. The inner panel 28 is flat in its normalposition. It is not completely impervious to moisture and has a tendencyto warp, bulge, or buckle when one side is wetted and the other sideretained in a dry condition.

The panel 28, when proper provisions are not taken to prevent suchaction, would bulge cutwardly when the refrigerator is in operation andthe door 02 is opened. During the operation of the refrigerator, theinner panel 28 of the door 40 I2 is cooled, and when the door i2 isopened and the dew point temperature of the ambient a r is above thetemperature of the inner panel 28. moisture from the air will condenseon the ex posed surface of the inner panel 28. When this moisturepenetrates the outer layers of the panel 28, the panel 28 bulgesoutwardly and may strike the shelving it in the refrigerator cabinetwhen the door it is again closed.

The outward bulging of the panel 23. according to this invention, isprevented by forcibly I dishing or pre-setting the panel 28 inwardly.The inward dishing of the panel 28 may he effected in numerous ways andin this embodiment of the invention is effected by a screw 3| insertedthrough an opening 32 formed approximately in the center of the panel28, which screw 3| engages a threaded hole 33 in the leg 24 of the brace2 I. The inward deflection of the central portion of the panel 28 isadjusted by turning the screw 3| by means of the screw driver slot 34.

It is obvious that the portion of the panel 28 near the screw 3| cannotbulge outwardly. In actual practice it has been found that not only theportion of the panel 28 near the screw 3| is held rigidly but also allother portions of the panel 28, even though remote from any point ofsupport, retain their original position when the refrigerator door I2 isopened. When the inner panel 28 is pre-set into a dished configuration,the expanding forces of the moistened outer layer of the panel 28 tendto bulge the panel further inwardly toward the outer door pan l6, ratherthan outwardly toward the shelves. The relative motion of the dishedpanel 28 when moistened will also be smaller than the relative motion ofa fiat panel under the same conditions.

It will be apparent from the above that this invention provides a simplemeans for preventing the bulging of panels of rigid panels of fiatheatinsulating material in refrigerators. It also provides a door for arefrigerator cabinet in'which low-cost panels of heat insulation aresatisfactorily utilized.

While I have shown my invention in but one form, it will be obvious tothose skilled in the art that it is not so limited, but is susceptibleof various changes and modifications without departing from the spiritthereof, and I desire,

. therefore, that only such limitations shall be placed thereupon as arespecifically set forth in the appended claims.

What I claim is:

1. The .inethod of fabricating a door for a refrigerator cabinet, saidmethod comprising securing a panel of stiff heat insulating material atits edges to a rigid door frame, said panel having a flat portion facingthe refrigerated chamber of the cabinet when the door is in use, anddistorting the flat portion of said panel into a dished configuration byforcibly drawing a small part of said portion, spaced from the edgesthereof, in a direction inwardly of said door and retaining said part insaid position, the fiat portion of said panel, between said part and theedges of said portion, being free to move inwardly or outwardly withrespect to the door.

2. The method of fabricating a door for a refrigerator cabinet, saidmethod comprising securing a substantially flat panel of stiffheat-insulating material at its edges to a rigid door frame forming apart of the outer member of said door, said panel facing therefrigerated chamber of the cabinet when the door is in use, anddistorting said panel into a dished configuration by forcibly drawing asmall portion of said panel spaced from said edges in a directioninwardly of said door and retaining said portion in said position, v

the portions of said panel between said firstnamed portion and the edgesof said panel being free to move inwardly or outwardly with respect tothe door.

3. The method of fabricating a door for a refrigerator cabinet, saidmethod comprising securing a substantially fiat panel of stiffheat-insulating material at its edges to a rigid door frame forming apart of the outer member of said door, said panel facing therefrigerated chamber of the cabinet when the door is in use, anddistorting said panel into a dished configuration by forcibly drawingthe central portion of said panel inwardly of saiddoor and retaining itin said position, the portions of said panel'between said centralportion and the edges of said panel being free to move inwardly oroutwardly with respect to the door.

4. In a refrigerator cabinet, the combination of a thin, normally flatpanel of relatively stiff heatinsulating material so positioned in therefrigerator cabinet that it is subjected to moisture on only one sidethereof, and a rigid member secured to said panel to distort the sameinto a dished configuration with the side subjected to moisture formingthe concave side of the panel to prevent bulging of the panel in theopposite direction, said rigid member being out of contact with themajor portion of said panel.

5. In a refrigerator cabinet, the combination of a rigid member, a thin,normally fiat panel of relatively stiff heat-insulating material sopositioned in the refrigerator cabinet that it is subjected to moistureon only one side thereof, means for securing the periphery of said panelto said rigid member, and means for distorting said panel into a dishedconfiguration with the side subjected to moisture forming the concaveside of the panel to prevent bulging in the opposite direction, saiddistorting means including the means for securing the periphery of thepanel and also including additional structure acting upon the panelwithin its periphery, said structure being out of contact with the majorportion of the panel.

6. In a door for a refrigerator having a refrigerated storage chamber,the combination of an outer door pan, an inner panel of a normally fiatrigid heat-insulating material so positioned that it is subjected tomoisture on the side thereof facing said refrigerated chamber when thedoor is in use, means forsecuring the periphery of said inner panel tothe edges of said outer door pan, and means for forcibly distorting saidpanel into a dished configuration with the side subjected to moistureforming the concave side of said panel to prevent bulging thereoftowards said refrigerated chamber said distorting means including themeans. for securing the periphery of the panel and also includingadditional structure acting upon the panel within its periphery, saidstructure being out of contact with the major portion of the panel. 7.In a door for a refrigerator having a refrigeratedstorage chamber the.combination of an outer dOOr panel, a normallyfiat inner panel of rigidheat-insulating material so positioned that it is subjected to moistureon the side thereof facing said refrigerated chamber, means for securingthe periphery of said-inner panel to the edges of said outer door pan,and means for forcibly distorting said panel into a dished configurationwith the side subjected to moisture forming the concave side, saiddistorting means comprising a rigid member disposed between the outerdoor pan and the inner panel and means for fastening only the center ofsaid inner panel to said rigid member.

8. In a door for a refrigerator, the combination of a dished metallicouter panel, inwardlyturned flanges on said panel, a brace secured atits ends to said flanges and extending across said panel atapproximately its mid-section, an inner panel of normally flat sheetmaterial secured at its edges to said flanges, said material tending tobulge outwardly away from said outer panel when said door is in serviceon a refrigerator, heat-insulating material between said inner andouter-panels, and means for securing said panel at approximately itscenter to said brace to forcibly dish said panel inwardly, therebytending to destroy the tendency of said material to bulge outwardly atunsecured portions thereof.

9. In a door for a refrigerator, the combination of a dished metallicouter panel, inwardlyturned flanges on said panel, a brace secured atits ends to said flanges and extending across said panel atapproximately its mid-section, an inner panel of normally flat sheetmaterial secured at its edges to said flanges, said material tending tobulge outwardly away from said outer panel when said door is in serviceon a refrigerator, heat-insulating material between said inner and outerpanels, a sealing gasket at the edges of the inner panel, and means forsecuring said panel at approximately its center to said brace toforcibly dish said panel inwardly, thereby tending to destroy thetendency of said material to bulge outwardly at unsecured portionsthereof.

10. The method of fabricating a door for a refrigerated chamber, saiddoor comprising a door frame and an initially fiat panel of stiflheatinsulating material secured at its edges to said door frame, saidpanel facing the refrigerated chamber, and when'in use and not otherwisesupported, tending to warp in a dished configuration with the convexside toward said chamber, said method comprising forcing the centralportion of said panel from its original fiat position so that said panelpresents a dished configuration with the concave side toward saidchamber,

said forcing being effected by a member of the door secured to saidframe and to only a small area of said panel remote from said frame.

JOHN H. ASHBAUGH.

